Thermostatic control circuit



Oct. 2, 1934. P. B. PARKS Er AL IERMOSTATIC CONTROL CIRCUIT N QN sw QN Filed Jan. 23. 1953 Patented et.' 2, i934 UNET remit' THIERMSTATIC CONTROL CKRCUHT Application January 23,

13 Claims.

This invention relates to certain new and useful improvements in a temperature regulating system, and more particularly to an automatically operating thermostatically controlled system comprising both a heating means and a refrigerating means, said system functioning to maintain selected temperatures within an enclosure. While the invention has been designed more particularly for use in a railway/car or other moving vehicle, many of the features thereof are equally adaptable for use with stationary enclosures, such as rooms of ordinary buildings.

Briefly described, the railway car which may be divided into a plurality of separate compartments is provided with an air circulating system comprising a passage into which air is withdrawn from the car and forced out at a plurality of selected locations by means of a power-driven blower. Separate heating and refrigerating means are positioned in this passage for regulating the temperature of this circulated air. Separate heating means are also provided for each of the separate compartments for independently regulating the temperature of the air in each of these compartments. Separate electrically operated thermostatically controlled mechanisms are provided for each of the several heating and refrigerating means, these control mechanisms being each manually adjustable to establish a predetermined selected temperature. Located at some convenient position in the car, or other structure to b e heated, is a panel board in or on which are positioned all of the relays and similar devices through which the several thermostatic mechanisms control the temperature regulating `devices. included among these devices grouped on the control panel is an automatic circuit breaker comprising a signallight which is illumihated when one of the actuating circuits is broken. By opening or closing test switches in the several circuits, the circuit in which trouble is located can quickly be determined by means of thissignal device. A thermostat positioned outside the car or lother enclosure and responsive to outside temperatures operates through a selector relay on the panel board to determine whether the heating means or the refrigerating means shall be elective at any one time. In the case of a railway car, a pressure operated selector switch` which is normally held open'by the iiuid pressure existing in some service pipe line on the car when the car is in service, operates throughthe selector relay on the panel board when vthe car is out of service to render the heating means incapable of maintaining more than a predetermined low 1933, Serial No. 653,073

temperature within the car. Other improved features of the invention will be more apparent from the detailed description given hereinafter.

The principal object of this invention is to provide an improved automatically operating thermostatically controlled apparatus for regulating the temperature within an enclosure, suoli as briefly described hereinabove and disclosed more in detail in the specifications which follow.

Another object is to provide a temperature regulating apparatus comprising heating means and cooling means, and thermostatic mechanism4 positioned outside the enclosure and responsive to outside temperatures for determining Whether the heating means or the cooling means shall be eiiectve.

Another object is to provide an improved thermostatic control mechanism in which the operating relays and associated mechanisms are grouped on a single control panel.

Another object is to provide such a control system with a single selector relay which cooperates with the several heatingand refrigerating mechanisms to determine whether or not the refrigerating means shall be operative, and to establish. a minimum temperature to be'maintained by cerltain of the heating mechanisms.

Another object is to provide means for controlling the voltage in certain of the circuits, and for automatically breaking certain of the other circuits when an excessive or prolonged current flows through these circuits.

Another object is to provide a single selector re.aywhich is alternatively controlled by either an outside thermostat or a pressure-operated switch for establishing a predetermined minimum temperature within the car whenever either the outside temperature has risen above a predetermined maximum, or'the car has been taken out o'f service.

Other objects and advantages of this invention will be more apparent from the following detail description of one approved mechanism constructed and operated according to the principles of this invention.

The accompanying drawing is in the form of a wiring diagram illustrating conventionally the construction and operation of the several com ponent parts of the system.

At A, B and C are indicated three separate compartments in the railway car. The compartment A may be a wash-room or lavatory, and the liti 2 hardere similar to the' compartments A or B, and that each of these compartments will belseparately equipped with temperature regulating mechanisms of the type hereinafter disclosed in each of these compartments. Thccompartment C indicates 'a separate Vspace or plurality of spaces, such as a closet at one end of the car, in which the control panel indicated at D and similar de- `vices may be conveniently grouped. A passage E is provided, preferably in the upper portion of the earkinto which air from within the car is drawn through the grilled opening l and discharged through separate openings such as 2 into the several compartments, A certain percentage of fresh air from outside the ear may be admitted to passoire E through a valved inlet opening such as indicated at 3. A fan or blower F, driven by a motor e, is provided for enforcing the circulation of air through passage E.

. Each compartment A and B is provided with a heating unit such as the radiator or radiators indicated at G and Cl', the circulation of steam or other heating medium through the radiators being controlled by the electrically operated distributinavalves H and H' respectively. A heating unit'G is positioned in theA passare E, the flow of heating medium to this unit being controlled by the valve H". A refrigeratina element such as indicated by the coil .l is also positioned in circulation passage E, the supply of refrigerant for coil J being provided by the refrilzerating mechanism K positioned at any convenient location on the car and driven by the motor 5.

A thermostatic control assembly indicated generally at L and provided with a manually oper- .able mechanism M for selecting the temperature to be maintained is positioned within the compartment A and cooperates with a control relay N on panel board D to operate the distributing valve H. Similar devices L', M and N are provided for eachcompartment B. The thermostatic assembly LI which through relay N" controls the valve H" for supplying heating medium to the radiator G, is positioned in passage E so O is positioned in'anycfonvenicnt location, preferablyadlacent the control mechanism Mv'. The power source indicated at R supplies electric power for'all of the control and motor mechanisms within the car, and through the voltage regulator indicated at S supplies power to the car lighting system indicated at T. At`U is indicated the main cut-out switch for the lighting system,

`and as will be hereinafter apparent this switch U when opened alsoopens somey of the control circuits hereinafter described. At W on the panel board is indicated an automatically rcciosing circuit breaker which is adapted to open the actuatim.; circuit for one or more oi' the valve operating mechanisms 1I whenever one of these valves sticks or otherwise becomes inoperative and an excessive current flowsthrough these circuits. The selector relay X on the panel board lcooperates with thc several .control relays N and P to determine whether thc heating means or the refrigerutinu means shall bc cii'ective, and to establish,

under' certain circumstances, a minimum ternperature to be maintained by the heating means. The selector relay X is controlled by a thermostat Y positioned outside of the car or other enclosure so as tovbe responsive to outside temperatures.

The relay X is also, and alternatively, under the control of a selector switch Z which is pressureopcrated and connected with a pipe line on the car which normally contains fluid under pressure when the car is in service.

Theseveral elements of this system, and the wiring connections therefor, will now be described somewhat more in detail. It is to be understood that all of the devices shown'in the drawing above the floor line 6 of the car will ordinarily be positioned' within the car or other enclosure, whereas the devices shown below this fioor line will ordinarily be positioned below the car or in some other convenient location out side-of the car compartments.

The source or power R is here shown simply as a storage battery, although it will be understooolthat, in the case of a railway ear,` a generator driven from theY running gear of the car will beprovided as usual to furnish power when the car is in motion and restore the battery.

The positive terminal of the battery is connected through a wire '7 with positive terminal 8 from which wire 9 leads to a positive-terminal 10 oi the voltage regulators. Wire 1l leads from the negative terminal of the battery to a negative terminal l2.

The voltage regulator S, which is of well known type, comprises a stack of resistance carbone 15, one terminal of which is connected through wire 16 with the terminal 10, the other terminal of the stack "being connected through wire 17 with a terminal 18 which is connected by wire 19 with a terminal 20. Aweight 21 is positioned on one arm 22 of a bellcrank lever. pivoted at 23, the other arm 24 of this bellcrank pressing against one end of the carbon stack 15 to cornpress the same and minimize the resistance thereof. The core 25 of a solenoid 26 is connected through stern 27 with the weighted arm of the bellcrank. When the solenoid is energized. the core 25 will be elevated so as to raise the weight 21 thereby decreasing'the pressure of arm 24 on the carbon resistance 15 so `as to' increase the eiiective resistance of this carbon stack. A partial circuit for energizing solenoid 26 leads from terminal 20 through wire 28, solenoid coil 26. wire 29, resistance 30, and Awire 31 to the terminal 14,'thence through wire 13 to fixed contact 36 of switch U and through wire 3'.' tothe negative terminal 12. y

When the main switch U is closed, the lights T may be energized through the following circuit: From positive terminal 8 through wire 9, terminal 10, wire 16, resistance stack 15, wire 17, terminal 18, wire 19, terminal 20, wire 32, movable arm 33 of cut-out switch U, wire 34, lights T, wir: 35. fixed terminal 36 of switch U, and wire 37 to the negative terminal 12. At the same time current willflow-through the parti'al shunt circuit already described which energizes solenoid 26. As the voltage tends to vincrease and a greater current flows through this solenoid-coil, the core 25 will be elevated so as to raisethe weight 21 and decrease the pressure on carbon stack i5, thereby increasing the resistance of this carbon stack which is interposed in the lighting circuit thereby decreasing vthe .effective voltage in the lighting circuit and maintaining this voltage at or below a predetermined maximum. It

intacta is to be understood that individual switch mechanisms will be provided for the component parts of the lighting system indicated generally at T, only the main cut-out switch U being Vshown'.

A main negative supply line 38 on the panel board' D connects at 39 to the wire 37leading to the negative terminal 12. Wire 41v leads from the main positive terminal 8 to the positive supply line 42 on the panel board which in turn leads to the circuit breaker W. The circuits supplied from wire 42 through the circuit breaker W do not extend through the voltage/regulator S. A

wire 43 leads from positive terminal 18 of the voltage regulator to the positive supply line 44 on the panel board from which the several thermostatic control circuits hereinafter described are energized. These circuits do not pass through the circuit breaker W, but the voltage in these control circuits is maintained below a predetermined maximum bythe regulator S.A

The blower-motor 4 is controlled by the switch 45 and is energized through the following circuit: From positive terminal 8 through wire 41,

wire 46, motor 4, Wire 47, switch 45, and Wires 48 and 37 to the negative terminal 12.

Each of the relays N, N and N comprises a `solenoid coil 49 which, when energized, will draw up a core 50 connected by stem 51 to a movable contact plate 52 so as to bring this contact plate into position to bridge a pair of ilxed contacts 53 and 54. When the coil 49 is deenergized, or insufficiently energized, the core 50 will drop so as to bring' Contact plate 52 into positionto bridge the fixed contacts 55 and 56. The solenoid coil 49 is normally energized so as to holdthe contact -plate 52 in its elevated position (as now y shown in connection with relays N and N") by means of a circuit extending from positive supply line 44 through wire 57, resistance 58, solenoid coil 49, resistance 59, and wire to the negative supply line 38. Wires 6l and 62 lead from the respective vterminals of solenoid coil 49 toa pair of binding posts 63 and 63' on the panel board D. Control circuits leading from the thermostatic mechanism L (or .the mechanisms L' or L" as the case may be) connect with the binding posts 63 and 63 so that when a certain predetermined temperature is reached in the compartment A (or compartment B or passage- E) the energizing circuit for solenoid coil 49 will be short-circuited through the thermostatic mechanism thereby deenergizing the solenoid and permitting the contact plate 52 to drop into' engagement with the lower fixed contacts 55 and 56.

(as shown for example in connection with the Each.l of the`thermostatic mechanismsr L, L

and L comprises a plurality of similar mercury tuber thermostats, inthe present example the three thermostats 64, 65`and 66. A`wire 67 leads from binding post 63 on the panel board and connects into the lower portion of each of the thermostats so as to be 'in constant engagement with the mercurycolumn therein. A terminal 68 is positioned in the tube of 'thermostat 64 (which may be -called the high temperature thermostat) so that this terminal will be engaged bythe mercury column when a temperature of, for'example, 72.Fahrenheit is reached in the compartment A. A'similar terminal 69 is xed in mercury tube 65 which may be called the mediumtemperature` thermostat so as to be engaged bythe mercury column of -this thermostat at a temperature of, for example, 70 Fahrenheit. Similarly Vthe xed contact 70 in the "low temperature thermostat 66 is engaged by the mercury column at a temperature of, for example, 60 Fahrenheit. By means of the manually adjusted switch' mechanism indicated generally at M the system may be placed under control of any one of these three thermost'ats'. This switch comprises an indicating lever 7l pivoted intermediately at 72 f and in constant engagement at its upper end with the fixed arcuate contact plate 73. The

other end oi lever 71 is adapted to engage alternatively with some one of the fixed contacts 74, 75 or 76. A wire 77 connects terminal 68 of the high temperature thermostat `with the iixed contact plate 73. A wire 78 connects wire 77,with the binding post 63' on the panel board. A wire 79 leads from fixed contact69 of the medium temperature thermostat to the xed contact 75, and

a wire 80 leads in a similar manner from fixed l shown in compartmentA, the medium temperature thermostat 65 will be in control. When the predetermined temperature is reached in the compartment A, a shunt circuit will be completed around the. solenoid coil 49 as follows: From binding post 63 through.` wires 78 and 77, contact plate 73, switch lever 7l, terminal 75, wire 79, thermostat 65, and wire 67 back to binding post 63. This will serve to deenergize the solenoid and permit the contact plate 52 to fall to its lower position in engagement with fixed contacts 55 and 56. This will complete an operating circuit which will move the valve H to a closed position, as hereinafter described. When the temperature in compartment A falls below the predetermined temperature for which thermostat 65 is set, the shunt circuit'just described will be broken at the terminal 69and solenoid 49 will again become energized so as to raise the contact plate 52 `into engagement with the fixed contacts` 53 and switch lever 71 is moved to the high position so that its lower end is in engagement with con-v tact 74, none of the circuits can be complete iOO through this lever and only the high-temperav ture. thermostat 64 is capable of completing a shunt circuit to deenergize the relay N. AIf switch lever,71 is moved to the low position so thatits lower end is in engagement with contact 76, a shunt circuit for deenergizing relay N will be completed as soon as the mercury column of low- 'temperature thermostat. 66 engages the fixed contact 70.

The valve H will thus be closed to cut off the ilow of 'heating medium to radiator G as soon as the temperature in compartment A has reached the comparatively low temperature for which thermostat 66 is set, and the temperature will never rise high enough to cause the medium or high temperature thermostats 65 or 64 tobe-eifective.

Inl an exactly similar manner the thermostatic assembly L in compartment B acts through relay N to control the valve H' which regulates the ilow of heating medium to the radiator G' in compartment B. It will be noted that the switch mechanism M in compartment B differs from the switch mechanism M in compartment A in lill having an additional "oil" position in which the upper end of switch lever 71 is in engagement with arcuate contact lplate 73 and the lower end in engagement with a xed contact 83. When in this position a shunt circuit for deenergizing the relay N is slways completed, regardless oi the thermostats L', through the following circuit: From binding post 33 through wire 73, wire 77, arcuate contact 73, switch lever 71, fixed contact 83, wire 84, end wire 67 to the binding post 53. This permits the heat to be entirely shut oi when desired. with the type of control shown in compartment A, the heat can never be ene tirely cut oil' by means oi the control mechanism M', but will always keep a minimum low temperature in the compartment.

The control mechanism M is similar to the control mechanism M and cooperates with the thermostatic assembly L in passage E and the relay N on the panel board to control the valve H, which in turn controls the dow oi. heating medium to the heating unit G in the air psssage E.

The electrically actuated valve-operating mechanisms for each oi the valves lifl and H are similar. end each comprises e pair oi solenoid motors 35 and 36. having cores 37 and 33, respectively, mounted at the opposite ends oi a slide rod 33 which is interrnediately connected with one arm of the valve operating lever 90. rl'he opposite enel oi lever is connected with a snap switch 91 having s movable contact arm 92 which is snapped out oi engagement with e hired contact 93 and into engagement with a xed contact 94 when valve-lever 90 reaches the open position shown in valve H, and which is snapped out of engagement with fixed contact Mund into engagement with fixed contact 93 as the valve reaches the closed position shown in valve H. The' ilxed contacts 93 and 9d oi the snap switch are connected through wires 95 and 96,`respec tively, with one terminal oi each of the solenoid coils 85 and 36. The other terminals oi these coils are connected through wires 97 and 98, respectively, with a pair oi binding posts` 99 and 100 on panel board D adjacent the relay N.' Wire 101 leads from binding post 99 to xed Vcontact 54 of the relay N. and wire 102 leads from binding post to the xed contact 56 of this relay. The wire 103 leads from the fixed contact 104i of the cir-' cuit breaker W on the panel board, and connects through the several wires 105 with the movable contact members 92 of the several snep switches 91 of the valve mechanisms. The two fixed contacts 53 and 55 of eachJeIay N are connected through wire 106 with the movable contact arm 10T-,01' a. cut-out or test switch, the fixed contact of which is connectedthrough wire 108 with the negative main 38 on the panel board.

The circuit breaker W is preferably of the automatic re-closing type disclosed more in detail and claimed in the copending application o! vParks and Miller, Serial No. 609,463, filed May 5,

1932. The current for the valve-operating circuit fiows from the positive terminal of the source of power R through wires 41 and 42, ther- X mal resistance 109, wire 110, fixed contact 111, movable 'contact plate 112, xed contact 104 and through wire 103 to and through one or morso! the respective valve-operating circuits, as hereinafter described. When an overload occurs in one A or more branches of the valve-operating circuits,

or when the circuit ows tor an excessive length of time, the thermal resistance 109 will heat the bi-metallic thermostatic bar 113 soXas to cause this l herders bar to warp end bring the movsble contest 111i into engagement with the hired contsct thus completing a shunt circuit extending through the solenoid coil 11d and wire 117 to the negstive main 33. The solenoid 116, when thus energized, will iiit the core 113 which is connected through stern il@ with the movable contact plete 11.2 so as to brealr the valve-operating circuits between the fixed contacts 111 and 10e. it the same time an energizing circuit will be compled through the signal light 123 (or equivalent signcl device) this circuit being as follows: From positive wire 119 through fixed contact 120. movable `contact plate i12, hired contact 121, wire 122, signal light 123, and wires 124 and lllto the negative main 38. rliie lomp 123 will remain lighted es long as the circuit brealrer is in open position. When the therrnoststic bar 113 cools, it will werp bach so es to separate the contacts 114 and 115 and breelr` the energizing circuit for solenoid 115, but menne (not here shown) ere provided to delay this ac tion sc that the main operating circuits will reu main broken for .an appreciable length ot time. When the solenoid 113 is thus deenergised, the movable contact plate 112 will again drop into engagement with the hired contacts 11i and 104 thus again completing the valve=opersting cir=u cuits. li the overload or other trouble stili re= mains in one or more oi these operating circuits, the thermostatic ber 113 will again be heated and will warp so as to close the energizing circuit for solenoid 116 thus again brealring the valve-openating circuit, and the lamp 123 will again be lighted to indicate this condition. .This cycle of events will repeat themselves until the trouble is eliminated.

ln describing the normal operation of one of the valve-operating mechanisms'we will assume that the parts are initially in the position shown in compartment A. The medium temperature thermostat 65 is in control, the temperature at this time is somewhat below the predetermined temperature for which this thermostat is set, and the velve H is open so that heating medium is being supplied to the radiator or radiators indicated at G. llt may here be stated that the valve H (or H' or H" as the case may be) comprises e casing 125 in which is a movable valve member controlled by the intermediately pivoted lever 90. In the example here shown, the valve being part oi a vapor heating system, steam or vapor flows 'Mill into the valve through pipe 126. and if-the valvey I is in the open position as shown iiows out through pipe 127 to and through the radiator G, then back to the valve casing through pipe 128, and out through pipe 129- to the vapor-regulator beneath the car. When the valve lever 90 is swung over to theopposite position, as shown in valve H' in compartment B, the valve will be closed and the steam will ow into casing 125' through pipe 126' and directly back to the vapor regulator through pipe 129'. but will not flow out through the radiator G. It may here be noted that while the valve H" may be positioned at any desired location 'in the car and operates-in the same manner as the valves H and H', it is connected through the pipes 12,7" and 128" with the radiator G" positioned in theV overheadair passage E.

Returning now to the description ot4 the heat.

ing system in compartment A, it will benoted that at this time the relay N is energized and the iso mostat will be' completed, the relay N will be short-circuited, and the movable contact plate 52 will drop so as to bridge the fixed contacts 55 and 56. A valve operating circuit'will now be completed as follows: From positive supply line 42 through the circuit breaker W, wire 103, wire 105, contacts 92 and 94 of snap switch 91, wire 96, solenoid motor 86, wires 98 and 102, nxed contact 56, movable contact 52 and fixed contact 55 of the relay N, wire 106, test switch 107, and wire 108 to the negative main 38. The solenoid motor 86 will now be energized to swing the valve to the closed position, and at the end of this movement the snap switch will be op# erated to'break the circuit just described between the contacts 92 and 94, the parts now being in the positions indicated in connection with valve H in compartment BW When the temperature in the compartment A falls again so as to break the control circuit through the thermostat 65, the relay coil 49 will again be energized to lift the vcontact plate 52 to the position shown in relay N, whereupon a second operating circuit will be completed as follows: As in the circuit last described through wire 105, contacts 92 and 93 of snap switch 91, wire 95, solenoid coil 85, wire 97, wire 101, fixed contact 54, movable contact 52 and xed contact 53 of relay N, and wire 106 to the negative main 38. The solenoid motor 85 will now be energized to return thel valve and associated parts to the positions now shown in connection with valve H.

It will be noted that Kin compartment B the high temperature thermostat 64 is in control, that this temperature has been reached in this compartment, and that the valve H is closed. In the air passage E, the system is under the control of the medium temperature thermostat, the temperature is still below the temperature for which this thermostatis set, and valve H" is open.

1t will be noted that a test,switch 107- is provided adjacent each relay N on the panel board,

and whichever valve-operating circuit is otherwise complete can be broken by opening this test-switch 107. As already noted, Whenever there is an excessive current flow in any of the valve-operating circuits, the circuit breaker W will operate to break this circuit and cause the signal lamp 123 to be lighted. By successively and separately opening the several test switches 107, and observing the action of the signal lamp 123 and circuit breaker W, the circuit-in which trouble occurs' may be localized. Until this trouble is eliminated, this particular valve mechanism may be cut out of operation by leaving open its switch 107, without affecting the con-` tinued operationfof any other portion of the control system.

When a car is taken out of service for any considerable length of time, it is not necessary or economical to maintain the compartments at one of the higher temperatures, but it is desirable in order to prevent injury to the car and its contents not to permit the temperature to drop below a certain predetermined low temperature, for example the temperature which is maintained by the low temperature thermostats 66. Means is provided, therefore, to automatically maintain all of the compartments at this low temperature when the car is out of service no matter what the positions of the several manually adjustable switches M may be. This portion of the mechanisms comprises the fluid-pressure operated selector switch Z, and the selector relay for example Fahrenheit, the mercury column land connected at its xed end 132 with one of the air pressure pipe lines on the car. A pair of spring contact members 133 and 134 are normally out of engagement with one another but are adapted to be bridged bya movable contact bar 135 carried by the caminember 136 pivoted at 137. The vertically movable bar 138 carries a roller 139 at itsupper end which bears against the cam 136, being held in this position by spring 140, and the lower end of bar 138 is connected through bellc'rank 141 and link 142 with the free end 131 of Bourdon tube 130. When normal'l iiuid pressure is present in the pipe line on the car, the Bourdon tube will be expanded to the position shown in the drawing, thereby pullingl down rod 138 so that the engagement of 'roller 139 with cam 136 will force the movable contact bar 135 up to the position shown in which it is out of contact with either of the spring contacts 133 and 134. When the car is out of service and air pressure in the pipe line is dissipated, the Bourdon tube 130 will coil inwardly or contract sov as to move the yroller 139 upwardly.` The upper surface of cam 136 will then. be engaged so as to snap the contact bar 135 downwardly into position to bridge the two spring contacts 133 and 134. y The selector relay X, positioned on the panel 105 board, comprises a solenoid coil 143 which when energized will draw up the core 144 connected bylstem 145 with the contact plate 146. This solenoid coil is normally energized over the fol= lowing circuit: From positive main 44 on the panel board through wire 147, resistance 143, binding post 149, solenoid coil 143, binding post 150, resistance 151, and wire 152 to the negative main 38. Several similar pairs of cooperating contact members 153, 154, 155 and 156 each comprise one xed contact member and one movable contact member carried by the movable plate 146. When solenoid 143 is energized and the plate 146 is held in the elevated position shown in the drawing, each of these pairs of contact members will be separated. When the solenoid 143 is deenergized, the plate 146 will be lowerw so as to bring the several pairs of contact meinbers into engagement and separately `complete a plurality of independent circuits. The two relatively movable contact members 153 are connected through wires 157 and 158 with the `two binding posts 63 and 82 associated with the relay N. In a similar manner, the. contact members 154 are respectively connected through wires 157 and 158 with the binding posts 63 and 82 of the relay N. i The outside thermostat Y is located in any suitable position outside of the car so as to be responsive to changes in the outside temperature, preferably being positioned in a protective casing beneath the car body. A wire 159 leads from one terminal,150 of solenoid 143 to a xed'contact member 160 in constant engagement with the 5 mercury column 161 of the thermostat Y. -An M0 upper contact member 162 of the thermostat iscnnected through wire 163 with the other terminal 149 of relay solenoid 143. When a certain predetermined outside temperature is reached,

161 will engage'the fixed contact 162 thereby completing a shunt circuit around the solenoid coil 143 so as to deenergize the same and permit the contact plate 146 to drop and bring together the several respective pairs of contact members 156 lil `out oi cervice and the fluid pressure'ia dissipated "lrorn the pipe with which Bourdon tuloc lilo is lill connected, the switch Z will he closed acari to complete a aeconol :shunt circuit which will deenergize the colector relay X. Whenever the car iawtalren out oi? cervice and the switch Z is closed eo aa to deenerize the relay X, an operating circuit fior low temperature thermostat @o in com pertinent A will he completed as ollowc: From ioindinc poet o3 through wire lo?, 4contacta loc., wire liiilioinding post d2. wire dlp low tempera ture 'thermostat do. andrwire 67 to binding poet d3. Tione,I even though the rnecllurn or high therrncctatc o5 or ofi rnay 'ce connected in cervice hy :switch M, an auxiliary operating circuit is thus completed through the low temperature thermostat (lo ao that the valve Trl will he operated to cut 'o the flow oi heating rnecliurn to radiator @l whenever the temperature in compartment l rises alcove the minimum temperature for which thermostat adjusted. ln other worde, no rnatter what rotting ci Switch Ni' may he, the compartment A will ice automatically maintained at a minimum temperature whencvcrlthe carie out oi cervice. VThe deeneraization or rel lay Si will complete a similar control circuit ior each of the compartimento A or E.

llt will loe noted that in the caee ol the relay lil" and therrnoatatlc aacenohly no interrnecli= ate hihi-.ling poet c2 or auxiliary wirt connection di lo provided, the hindini,7 poete 63 and c3' or the relay N are connected cy wirea lo@ and lo? with the pair oi relatively rnovaiole contacta i553 or relay when there contacte 155 are brought into engagement hy the chort circuitinig or oolenoid'lc, the relay N" will loe directly de energized co ae to chut oir the valve il"v no 'matter what the temperature conditions ailectingv the therrnoetatc la may loe. ic unneceesiary to maintain any ininirourn temperature in the pac cage when the car la out ci cervice, and iurther= incre it laundcairalzile that the radiator chouid operate at all when the refrigeration unit o" ie in operation. rFor this reason the connectiona are auch that the colector relay X will completely cui; ci? the radiator G whenever the car la teiten out ci cervice or the outside therrnoatat Y rcfzicterc a predetermined maximum outeideteniperature. n The thermoctatic afieernioly C? which controlo the refrigeration niechanicrriv may he auhritan= tiolly the carne w any one oi the coccinelles la, cornprieinaq a high temperature thermostat ide, intermediate temperature thermostat le@ and a low temperature thernloatat li'o. The manually adiuetalole switch mechanicrn Q ie essentially the carne ae the mechanisme M previously described,

' and according to the adjustment of thia Switch mechanism 'one or the other oi7 the thi'rrioctetc will.A at a predetermined temperature. complete a circuit between the two wires i'li and 172 which leadv to the panel hoard. When switch mecha= nicrn Q io moved to the soi-called "on" position. a permanent connection between wires ll and i722 la established eo that the refrigeration rnecha anicin will loe operative no matter what the tern= perature adjustments of the thermoatcte may loe.

Viriaeratini; rncchanicm will loe inoperative.

e :hardere The relay assembly l? on the panel board corn-1 priccs a pilot relay coil 173 whlchrwill he ener= sized, whenever a circuit is completed between wirca l'll and 172 Ythrcuah the thermostat O or switch Q, lloy current ilowinr, over the following circuit: From positive main ilithroufgh wire 174i, contacts 15o o selector relay X, wire 175,"reeistancc i'lc. wire l72, wire 1.7i, solenoid coil i713. and wires i7?, i3 and 3'` to the negative terminal l2.Y lt will loe noted that this control circuit cannot he completed unlcsathe selector re lay ii is dcenergizcol and the contacts 156 are brought in encingehicnt.Y This will he accorn= plichcci when the outside temperature has ricen aioovc a certain predetermined temperature, lor example '10" Fal/ironheit. co as to cicale the cir= cuit through outside thermostat Y. Until thia outside temperature has been reached. there= The cnercization of pilot relay collilii willdraw up the core oi' this relay which is connected through stem li with movable contact member i725 which will he lifted into engagement with a fixed contact eo ae to complete an energizing cir cuit for thornaln relay coll lill, aa follows: From positive rnain lo through wire iiifl, aolencid coil lol, wire E53, movable contact member ille. fixed contact lilo, and wire 'lofi tothe negative main lii which leacle to the iixecl contact lilo ci ewitch i5 in the actuating circuit hlower- I motor it will thun be eeen that thia relay circuit cannot loe completed unleca the awitch l5 la cloned to put the "clower motor i in operation. lt might here he noted that the negative aide oi the'control circuito for heating relay N are alec completed through this wire lea inateacl oi through the main negative connection on the panel hoard. The result ic that neither the heat mechanism nor the reiriceratinfr rnechaniain inpaeeaae il will operative unicas-i the blower rector c le put in operation hy closing the :switch When the relay coll lill ia energized. it will liit the movable contact plato liil into engagem nicht with fixed contacto and thun completing an actuating circuit lor the reiricere ating motor c aa follows-i: lroni po: tive ll2 through wire loll, rlxed contact rnovaiole contact le?, contact lilo.y ,rire prescrire ewitch ice. wire lilo to the negative niain Sie,

it will thus loe eeen that whenever the temperature ci the air stream"fiowinc'fthrouirh arcane riesce alcove 'the temperature :for which ther= rnoetatic aeoernhly G iii adjusted, a circuit will he cloaed to energize pilot rootor lili which in turnlwili energize the main relay coil ici. thuis closing the actuating circuit for rerlgerating rnotor il. When the temperature lowered ao aa to irreali the controlcircuit through the thernioctat which ie in control, these :several circuito will he successively iorolren and the inoI tor 5 will cease to operate.

Brieily reviewing come of the rnain featurea of thic temperature regulating eyetern;V it will he noted that the only portions oi the control cya= tern normally acceeeiioic to the occupante of the compartment will he the manually adjustable ewitchce lifl or M in the ccvcrai compartimento A and E. By rneane of there ewitchec the tern= peraturec may be normally adjusted to cuit the desire oi? the occupants. In corne compartments euch ae E, provided with a'ewitch mechanism of the type chown at M'. the heat may be entirely cut oil iiiidesired. except ier the tempered air lilo X so

admitted through the grille 2 from passage 3. ln some public rooms such as compartment A, it may not be desirable to permit any unauthorized person to entirely cutoff the heat,l and for this reason the switch mechanism M is only capable of reducing the temperature maintained to a predetermined minimum. It will be understood that there may be a plurality oi each type of compartments A and B, and that each o these will be provided with a control system of the type here shown, all of`these systems being controlled throughthe panel board G. When the car is out of service, the selector switch Z will operate through selector relay X to cause a certain predetermined minimum temperature to be' maintained in all ci' the compartments A and B. The temperature controlling systems G" and J in the air circulation passage E will neither of them be operative until the Iblower F is put in operation. The refrlgerating mechanisms J and K are inoperative until the outside temperature has risen above a predetermined maximum for which thermostat Y is set. When the outside temperature rises above the predetermined maxiymum, the heating means G" in passage E will be renderedentirely inoperative, and the several heating means Gand G' in the compartments.

will only be operative to maintain ac'ertain predeteed minimum temperature. Since, the rerigerating means will neveryr lower the temperature to this minimum, the heating means in the compartments are practically inoperative under these conditions. In this manner a single selector relay X is adapted to cooperate with both the pressure-operated selector switch Z and the outside thermostat Y in order to selectively control the-operations of the heating and refrigerating mechanisms. ln general, all of the mechanisms grouped on the panel iboard D and thev other devices shown in compartment C will only be accessible to the porter orl other authorized attendant.

It will be noted that the circuits which include the several thermostatic assemblies and relay mechanisms are entirely independent oi the operating circuits ior the valves H, although both derive their energy from the same source oi long length of time, the circuit brealrer W willA operate to temporarily interrupt this operating circuit. After a certain lapse of time this automatically reclosing circuit breaker will operateto again complete this circuit and in case the trouble is only temporary the circuit will remain closed, but if the trouble still-exists, the circuit will again be interrupted and this cycle of events will repeat itself, the signal lamp 123 flashing on and on at intervals to give visible indication of this condition.' It would be undesirable to have the thermostatic control and relay circuits interrupted in this manner since the momentary making and breaking of these circuits would be apt to cause incomplete impulses to be given to the valve opererating mechanisms which would leave the valves in intermediate or partly opened or closed positions, thus rendering the heating systems'inoperative or not properly eiiective. For this reason Leraars 27 the thermostatic circuits Ydo not include the automatic circuit breaker W but are continuously closed, although the'currents which flow through the thermostatsare kept below a predetermined safe maximum byvmeans of the voltage regulator,

S which also functions to maintain a proper voltage in the lighting circuit T.

In case trouble develops in one of the .valveoperating circuits, as indicated by the ashing of signal light 123 on the panelboard, the attendant may, by successively opening the cut-out or snap switches 107 and observing the action of the signal light 123, localize the particular circuit in which the trouble is occurring, and this circuit may bev temporarily out out of service by leaving the switch 107 open until the trouble is removed without aiecting the operation ci the other circuits.

In order that the refrigerating mechanism and control connections may be tested when the selector relay X is. energized or open, a normally open test 'switch 196 is provided to temporarily' connect the`fwires 174 and 175.

Under some conditions it may be desirable to raise the temperature of certain portions of the car above the minimum provided by thermostats 66 when the car is out of service. For this purpose, the selector switch Z is provided with a cam lever 197 whichmay be rotated by knob 198 into engagement with spring contact 134 so as to move this' contact out of engagement with contact bar 135 and break the shunt circuit through the switch Z. The control devices L and M will then be operative in the normal manner to maintain any selected temperature, as when the car is in service and switch Z is held open by huid-pressure.

We claim:

1. Apparatus for regulating within an enclosure comprising a heating means. a reirigerating means, electrically operated control mechanism for each of these means for maintaining a `selected one of a plurality of predetermined temperatures within the enclosure, a thermostat positioned outside the enclosure, and electrically operated means including a circuit in vwhich the thermostat is positioned cooperating with the control mechanism for, rendering the refrigerating means effective and limiting the heating means to the maintenance of a predetermined minimum temperature when the outside temperature is above a predetermined maximum,

and tor rendering the reirigerating` means ineective and the heating means effective tc mainy tain higher selected temperatures when the outside temperature is below the predetermined maximum.

2. Apparatus for regulating the temperature within an enclosure comprising a passage through which air is circulated from and baclr into the enclosure, a blower :for enforcing a circulation of the temperature air through the passage, a motor for operating the blower, a heating means and a reirigerating means in the passage, electrically operated control mechanisms for each of these means for maintaining selected predetermined temperatures within the enclosure, an actuating circuitfor the motor, and means including a switch in this actuating circuit for rendering the control mechanisms ineffective when theblower is not in operation.

3. Apparatus for regulating the temperature within an enclosure comprising a passage through which air is circulated from and back into the enclosure, va, blower for enforcing a circulation of airthrough the passage, a motorior operating the blower, a heating means and apreirigerating means in the passage, an actuating circuitfor the means within the passage, and separate mechanisms, one for each compartment, each comprising a thermostatic means responsive to temperature changes in the compartment for separately controlling the heating means in that compartment to maintain a selected predetermined temperature in that compartment.

12. Apparatus for regulating the temperature Within an enclosure divided into a plurality of separate compartments, comprising a passage through which air is circulated, said passage having an inlet leading from the enclosure and an inlet from the outside air, and a plurality of outlets leading separately into the several compartments, a blower for enforcing a circulation of air through the passage, a heating means in the passage, a separate heating means in each compartment, mechanism comprising thermostatic means positioned in the passage and responsive to the temperature of the air drawn into the passage for controlling the heating means within the passage, separate mechanisms, one for each compartment, each comprising a thermostatic means responsive to temperature changes in the compartment for separately controlling the heating means in that compartment to maintain a selected predetermined temperature in that compartment, and means comprising a thermostat positioned outside the enclosure and responsive to a predetermined maximum outside temperature Ifor cooperating with the several thermostatic means to render the heating means in the passage temporarily inoperative, and the several heating means in the compartments operative only to maintain a predetermined minimum temperature.

13. Apparatus for regulating the temperature within an enclosure divided into a plurality of separate compartments, comprising a passage through which air is circulated, said passage having an inlet leading from the enclosure and an inlet from the outside air, and a plurality of outlets leading separately into the several compartments, a blower for enforcing a circulation of air through the passage, a heating means in the passage, a refrigerating means in the passage, mechanism comprising thermostatlc means in the passage and responsive to the temperature of the air drawn into the passage for controlling the heating and refrigerating means therein to maintain the air discharged into the compart- A ments at a selected predetermined temperature, a separate heating means in each compartment, separate mechanism for each compartment comprising thermostatic means responsive to temperature changes in that compartment for controlling the heating means in the compartment to separately maintain a selected predetermined temperature therein, and meansA comprising a thermostat positioned outside the enclosure and cooperating with the thermostatic means within the enclosure to render the heating means ineffective when a predetermined maximum outside temperature is reached, and to render the refrigerating means ineffective when the outside temperature is below this predetermined maximum.

vPAUL B. PARKS.

WILLIAM M. SMITH. 

